We've all seen it happen. A great technology, service, or platform comes out, but without a solid base of users and apps, it fails to gain traction. Google wants to see the Fit API work out, and developers have been called upon to help make that happen. If you know how to write an Android app, and you've got a great idea for something that will get people off the couch and into the gym, you're invited to join the Google Fit Developer Challenge.

If you want to wear something that can provide a rough estimate of how active you are each day, there are noshortageofoptions. Now Jawbone is giving consumers two more. The company has announced a couple of activity trackers that it hopes will appeal to different types of people, with one of them showing off some rather advanced tech.

For starters, we have the $49.99 UP MOVE, an entry-level alternative to Jawbone's fitness bands.

LG and Samsung got the Android Wear party started, releasing the G Watch and Gear Live, respectively. Those watches only need Google's Wear app to function, but Motorola changed the formula a bit with the Moto 360, tying the watch to the existing Motorola Connect app. For the upcoming ZenWatch, ASUS is beating them all (well, sort of) with three separate watch-focused apps.

The first new ASUS app is simply titled "ZenWatch Manager," and it's essentially a remote setup function for your watch on your phone screen.

The tech giants are all pushing out fitness platforms of their own these days. Apple has HealthKit, Google recently flipped the on switch for Fit, and now Microsoft is bringing us Health.

Microsoft Health can track your steps, heart rate, calories burned, and sleep quality. If this sounds similar to Fitbit, there's a reason for this. The folks at Redmond are introducing an activity tracker of their own called the Microsoft Band.

My love for Runtastic grows by the day. Not only is the service very useful to track my runs and hikes, but its Android app is almost always on the forefront of the latest Google and Android features and guidelines. Case in point: it was one of the first fitness apps to add support for Android Wear and it just got updated with Google Fit integration.

The first time you launch the app you'll be asked to give it access to your Google account (or you can find the option under Settings, Partner Accounts) so it can view and store activity information, location data, and body sensor data (presumably heart rate stats).

After reports of skin rashes pushed Fitbit to recall its Force activity tracker at the beginning of this year, the company is now ready to bring the product's replacement to market. It's called the Charge, and it's joined by two other fitness bracelets packing more features and a higher cost.

The Charge comes with largely the same look and capabilities as the Force it replaces, providing the ability to track steps, follow sleep patterns, count floors climbed, see calories burned, and know who's calling.

Google Fit is something Google has been working diligently on since before its announcement at Google I/O. The service itself doesn't seem to be very well-rounded yet, but with a preview SDK available to developers for a few months and an app in the works, it seems like things are headed in the right direction.

We've seen only glimpses of the Fit app so far from leaked product reviews and comparison videos, but now that the whole app has been made available in a leaked Nexus 6 dump that's floating around (we're not going to distribute test-keys signed APKs), we can finally take a quick look at the app itself.

Active folks who fire up the latest version of the Fitbit app will see a new section tucked away in the sidebar: Challenges. Contained within is a way to take the fitness-minded company's Android experience and make it more social. Users now have the ability to challenge up to 10 people and compete with them in any of three contests.

Fitbit wearers can compete to see who can complete the most steps in a single day, over the weekend, or throughout an entire work week.

Late yesterday, Google began rolling out an update to the Android Wear companion app. Despite a sudden growth of over 2 MB in size, the app only seemed to change the text of a warning, and there were no visible changes on our watches. We knew there had to be something great hidden under the covers, and we were right. The companion app certainly has some interesting changes of its own, but it also acts as the delivery mechanism for a Wear-customized version of Google Play services, and there's a bit to talk about in there, too.

The Samsung Gear Live launched with a built-in heart rate monitor, but unfortunately, it could only take measurements one at a time. There was no way to monitor a wearer's heart rate continuously, such as during a workout. Now developer Portable Pixels has hit Google Play with an Android app that makes this functionality possible, one that goes by the rather straightforward name of "Heart Rate Training."

The developer's previous creations skew more towards the amusing side, but that doesn't limit the capability of this app.